China's Li Xiaoxia, 24, beat Japanese youngster Kasumi Ishikawa 4-1 to join her team-mate Ding Ning, world number one, in Wednesday's final.
"This represents a new generation of table tennis in China," Li said after her win, through a translator.
A win at London 2012 will extend China's faultless record since table tennis became an Olympic sport in Seoul in 1988. It also sets the country up to repeat a clean-sweep of the four golds it achieved on home soil four years ago.
With the pressure off, both players said it should be a good final for an estimated 500 million people viewing at home.
"I'm not going to feel pressured because the gold medal is in our team already, for China. I'm going to show my best to the world," Li said.
Ding, 22, has won most of the past matches between the pair. "I think both of us will be really going for it," she said.
They will see each other tonight, which Li said will be "a normal conversation", but they will not train together before the final.
Ding also comfortably won her semi-final, 4-2 against Singapore's Feng Tianwei, who was cheered on by Singaporean President Tony Tan Keng Yam in the crowd.
The game included a show of sportsmanship by the Chinese player when she was adjudged to have won a match point in game six, but she told the umpire it was actually Feng's point.
"The umpire judged that I had won but I noticed the ball had caught on the edge so I pointed it out. You could say that I felt better pointing it out," Ding said.
Ding dropped three sets in her three games on the way to the final, Li has dropped just two.
Both players are keen to etch their name in a table tennis record book jam-packed full of Chinese success, including past Olympic winners Deng Yaping and Zhang Yining.
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